Clamp and cutter mechanism for knitting machines



May 21, 1963 E. R. ZIEMBA ETAL 3,090,217

CLAMP AND CUTTER MECHANISM FOR KNITTING MACHINES Filed Dec. 28, 1960 5 Sheets-Sheet 1 FlE- l 1 45 47 16 I flea/116.4 I

g z 14 '35 35 I i A I g a INVENTORS [o waro R. Z/emba John C. Are/:62

ATTORNEY.

May 21, 1963 I E. R. ZIEMBA ETAL 3,090,217

CLAMP AND CUTTER MECHANISM FOR KNITTING MACHINES Filed Dec. 28, 1960 5 Sheets-Sheet 2 INVENTORS fo a/aro A? Ziemba John C- Are/7232 May 21, 1963 E. R. ZIEMBA ETAL CLAMP AND CUTTER MECHANISM FOR KNITTING MACHINES Filed Dec. 28, 1960 5 Sheets-Sheet 4 Q mm Y M 744 m d w n w o VF J May 21, 1963 E. R. ZIEMBA ETAL Filed Dec. 28, 1960 5 Sheets-Sheet 5 JNVEN TOR-S MAM/4M A TTORNE Y United States Patent U 3,090,217 CLAMP AND (IUTTER MECHANISM FOR KNITTING MACHINES Edward R. Ziemba, West Lawn, and John C. Arentz, West Reading, Pa., assignors to Textiie Machine Works, Wyomissing, Pa, a corporation of Pennsylvania Fiied Dec. 28, 1960, Ser. No. 79,003 Claims. (Cl. 66-140) This invention relates to knitting machines having yarn feeding and changing mechanism and more particularly to means in such machines for clamping and severing the yarns between the feeding means and the fabric at times when the yarns are moved to non-knitting positions and at other times preventing clamping and severing the yarns when moved to non-knitting positions.

In knitting machines and particularly machines of the type having a circular series of needles for knitting patterned tubular fabric such as for stockings, the yarn feeding means is operated by pattern means to introduce the yarns into and to remove them from knitting action according to the desired pattern. In the usual practice, when a yarn is to be removed from knitting action the feeding finger for the yarn is raised to position it in the path of clamping and severing means. The yarn is then carried by the last needle to knit it into the clamping means and between the cutting blades of the severing means which are first opened to receive the yarn and then closed to cut the yarn between the clamping means and the fabric under the control of pattern means having the same operating sequence as the pattern means for the yarn feeding means. In another form of means for controlling the operation of the severing means the cutting blades of the severing means are normally maintained in open position to receive the yarn and the blades are then closed to sever the yarn by operating means which is controlled and operated by the yarn itself.

While the prior clamping and severing means are suitably employed in the knitting of plain fabric and design patterns of the type generally referred to as Argyle or Intarsia in which the yarns remain in knitting action continuously until they are to be removed from the fabric, in knitting patterns such as Argyle incorporating overplaid designs in which the yarns forming the overplaid designs are momentarily moved to idle or non-knitting positions without being removed from the fabric, the use of the prior clamping and severing means was found to be unsatisfactory inasmuch as the momentarily idled yarns were also acted on by the clamping and severing means. Consequently, on machines for knitting design patterns where the yarns are only idled in non-knitting position but not removed from the fabric it is necessary to eliminate the clamping and cutting means and the stocking fabrics are knit in so-called string form in which all of the yarns used in the fabrics remain attached to the fabrics and float at the inside thereof between the points that the yarns are removed and again reintroduced into knitting action in the same fabric or in the next fabric in the string. This not only results in a considerable waste of yarn but also necessitates additional operations upon the completion of knitting to sever the individual fabrics from each other and to sever the waste yarn floats from the individual fabrics thereby greatly increasing the cost of the completed fabrics.

It is an object of the invention to provide a circular knitting machine with means which will overcome the above mentioned and other objections encountered in the formation of design patterns in knitted fabrics which require the movement of the design yarns to idle nonknitting positions at times when they are not to be clamped and severed from the fabric.

Another object of the invention is the provision of means in a circular knitting machine Which means acts in conjunction with the yarn clamping and severing means to at times prevent clamping and severing of yarns moved to idle or non-knitting positions and at other times to permit clamping and severing of the yarns moved to non-knitting positions for removal from the fabric.

A further object of the invention is the provision of means in a circular knitting machine acting in conjunction with yarn clamping and severing means, which means includes a guard member and pattern means for at times positioning the guard member in the path of yarns moved to non-knitting position to prevent entrance into the clamping and severing means and at other times to move the guard member out of the path of yarns moved to non-knitting positions to permit their entrance into clamping and severing means to be clamped and severed thereby.

A still further object is the provision of means for operating the yarn clamping and severing means of a circular knitting machine which includes an electrical circuit having a first switch which when closed by pattern means energizes the electrical circuit and opens the clamping and severing means to receive yarns to be taken out of action and severed, a second switch which is conditioned when the clamping and severing means is opened to maintain the electrical circuit energized and means operated by the yarns to be clamped and severed for opening the second switch to de-energize the electrical circuit thereby permitting the clamping and severing means to close and clamp and sever the yarns.

With these and other objects in View which will become apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings, the invention resides in the novel elements, features of construction and arrangement of parts in cooperative relationship as hereinafter more particularly pointed out in the claims.

In the drawings:

FIGURE 1 is a top plan view of a portion of a multifeed circular knitting machine illustrating the yarn feeding means at each of the feeds and yarn control and severing means in accordance with the invention;

FIG. 2 is a view partially in cross section and partially in elevation showing the yarn control and severing means taken substantially along the line and in the direction of the arrows 22 of FIG. 1, FIG. 2 being shown enlarged relative to FIG. 1;

FIG. 3 is a cross-sectional view on an enlarged scale taken along the line 33 of FIG. 1;

FIG. 4 is a view on an enlarged scale of the yarn control and severing device of FIG. 2 with a portion of the cover member of the device being broken away;

FIG. 5 is a cross-sectional view taken along the line 5--5 of FIG. 4;

FIG. 6 is an elevational view of a portion of the mechanism of FIG. 5 taken in the direction of the arrows 66;

FIG. 7 is a view of the mechanism as seen from the right of FIG. 6;

FIG. 8 is a view similar to FIG. 6 but with the parts shown in diflerent positions relative to FIG. 6;

FIG. 9 is a view of the mechanism as seen from the right of FIG. 8;

FIG. 10 is a cross-sectional view taken on the line 10-10 of FIG. 4 in the direction indicated by the arrows;

FIG. 11 is a view on an enlarged scale of a portion of the mechanism of FIG. 1;

FIG. 12 is a front elevational view of the mechanism of FIG. 11;

FIG. 13 is a view partially in cross section and partially in elevation taken along the line 1313 of FIG. 12 in the direction indicated by the arrows;

FIG. 14 is a view diagrammatically illustrating an electrical control circuit for the yarn severing means at one of the feed stations; and

FIG. 15 is a view of control means for a modified form of electrical control circuit for the yarn severing means.

Referring to the drawings and more particularly to FIGS. 1 and 2 thereof, the invention is shown as applied to a circular knitting machine having a plurality of feed or knitting stations, of the type shown and described in a patent application of Benjamin Franklin Coile, Serial No. 329,801, filed January 6, 1953 and in the corresponding British Patent No. 790,141 published February 5, 1958, hereinafter collectively referred to as the Coile Disclosure, to which reference may be made for details of construction and operation not shown herein. It will be understood, however, that the invention is similarly applicable to other circular knitting machines, the machine of said Coile Disclosure being selected for purposes of illustration only. The machine shown includes needles 15 which are slidably mounted for vertical movement in slots 16 in a needle cylinder 17 which is adapted for both rotary and reciprocatory motion. Cooperating with the needles 15 are sinkers or web holders 20 which are supported for horizontal sliding movement between the needles in radial slots in an inner ring 21 secured to the upper end of the needle cylinder 17 and an outer ring 22 secured to a flange '25 projecting outwardly from the cylinder. The sinkers 20 are maintained in position in the slots by a ring member 26 having cams, one of which is shown at 27 in FIG. 2, for operating the sinkers, and the needles are operated by cams (not shown) to cooperate with the sinkers to form yarns into fabric loops in a common manner at each of the feed stations.

Yarns such as indicated at 30 (FIG. are fed to the needles 15 through yarn fingers 31 at each of the four feeding stations indicated generally as feed Nos. 1, 2, 3 and 4, the fingers being pivotally mounted for movement between lowered or active positions. in which the yarns are taken by the needles and knitted into loops and raised inactive or non-knitting positions. The fingers 31 at each of the feeding stations are supported for their pivotal movement in a bracket 32 secured to the ring member 26 and are operated between the active and inactive positions by a button drum 35 rotatably mounted on a shaft 36. The ends of the shaft 36 are secured to arms 37 which are adjustably carried on vertically extending studs '40 secured in fixed position in the machine. The button drum 35 is rotated or indexed in a stepwise manner by an associated pawl and ratchet device 41 mounted on the shaft 36 and the pawl and ratchet device is selectively operated by connections (not shown) from main pattern drums 42 and 45 (FIG. 1) of the machine. With the exception of the arrangement of the buttons on the drum 35, the operating means for the fingers 31 at each of the feed stations are identical and are given like reference characters.

In addition to the movement of the yarn fingers 31 from active positions in which the yarns thereof are fed to the needles ls and inactive or non-knitting positions in which the yarns are to be removed from the fabric at each of the feed stations by the button drums 35, certain of the yarn fingers, after being moved to active positions, are adapted to be moved from such active positions to non-knitting positions during either single or double reciprocatory knitting strokes of the needle cylinder 17 the yarns fed thereby remaining connected to the fabric, such operations being performed in the manner and by the means set forth in US. Patent No. 2,948,131, issued August 9, 1960. As fully shown and described in said US. Patent No. 2,948,131 and as briefiy shown and described herein the end or outside fingers 31 of the group of fingers at each of the feed stations are provided with a pin 46 projecting therefrom for engagement with one of a spaced pair ofcam members 47 carried on a ring 50 supported on the ring member 26. The ring 519 is adapted to be moved by means (not shown herein) operating in timed relation to the movement of the needle cylinder to alternately move the end fingers to inactive positions so that while one finger is feeding its yarn to the needles the other finger is in non-feeding position.

Normally when a yarn is to be removed from the fabric, the finger 31 therefor is raised to a position above a binder plate 52 forming part of a device indicated generally at 51, and the yarn is then carried along the upper surface of the binder plate to be acted on by clamping and severing means associated with each of the feed stations and also forming par-ts of device 51, the yarn first being clamped and then severed. The yarn is then held by the clamping means until it is again returned to active position to be knitted into the same fabric or into the next fabric to be formed. The device 5 1 includes the binder plate 52 which is carried on a block 55 which is in turn carried on a vertically extending rod 56. The block 55 forms a part of a framework 57 having an upper member 60 and spacing fins 61 secured to the upper member and block. The rod 56 and framework 57 are supported on an arm 62 which is secured to a bracket 65 pivotally mounted on a pin 66 carried in a bearing member 67. The bearing member 67 is supported intermediate feed stations Nos. 2 and 3 (FIG. 1) on arms adjustably secured to adjacent studs 40 at these stations. The device 51, through arm 62 and bracket 65, is adapted to be moved from the lowered active portion of FIGS. 2 and 3, in which position a releasable latch pin 63 carried in the bracket 65 engages a stop surface 64 formed on the bearing member 67, and a raised inactive position as determined by engagement of the latch pin withra second stop surface 68 formed on the bearing member. A lever 69 pivoted on the bracket 65 is adapted to move the latch pin 63 to its released position to permit the movement of the device 51 between its active and inactive positions and a spring 74 acting on the latch pin returns the latter into latching engagement with the stop surfaces to maintain the device in its different positions (FIG. 3).

To hold the inactive yarns at each of the feed stations, a clamping member 71 and a clamping finger are provided for each feed, the member and finger cooperating with :binder plate 52. Clamping member 71 is pivotally mounted on a shouldered stud 72 between the head thereof and a head portion 73 of a second stud 74 secured to the block 55, the stud 72 being threadably carried in the stud 74. A spring 76 connected between an arm 77 of the clamping member 71 and a spring stud 80' carried in the block 55 biases the clamping member clockwise, as viewed in FIGS. 4 and 6, into clamping engagement with the yarns and binder plate 52. The clamping member is adapted to be moved counterclockwise against the action of the spring 76 to release the yarns for purposes of and in a manner hereinafter set forth. The clamping finger 75 is pivotally mounted in the block 55 and is biased into clamping engagement with the yarns at all times by a spring 8 1 connected between the clamping finger and a like clamping finger for the yarns at the adjacent feed station (FIG. 5). The clamping member 71 and clamping finger 75 associated with each feed sttaion are identical and like parts are given iike reference characters.

The means for severing the yarns at each of the feed stations includes a lower cutting blade 82 which is secured in fixed position to the block 55 and an upper cutting blade 85 pivota-lly mounted on the stud 74 :at the adjacent feed station. A coil spring 86 carried on the stud 74 between the head portion 73 thereof and the upper cutting blade 85 urges the latter toward shearing engagement with the iower cutting blade 82. The upper cutting blade 85 is moved between an open position (FIG. 9) to receive the yarns to be severed and a closed yarn severing position (FIG. 7) by a rod 87 connected between the blade 85 and and the lower end of a core member 90 of a solenoid 91.

The solenoid 91 is secured to one of the fins 61 by screws 92, as shown in FIG. 10.

As diagrammatically illustrated in FIG. 14, the solenoid is in an electrical circuit including leads 95 and 96 which may be connected .to the main source of electrical energy for the machine in any well known manner. The lead 95 is connected through a conductor 99 to one end of a coil or winding 97 of the solenoid 91 and the other end of the winding is connected to the lead '96 through a conductor 100 and a normally open micro-switch 101. The winding 97 is also connected to the lead 96 through a conductor 102 and a normally closed microswitch 105. The micro-switch 101 is carried, together with the corresponding micro-switches for the cutters of the other teed stations, in a housing member 106- which is secured by screws 107 to a fixed part of the machine adjacent the pattern drum 42 (FIGS. 1, 11, 12 and 13) and has a contact button 110 which is adapted to be engaged by a spring arm 111 carried on the micro-switch. The spring arm 111 is engaged [and operated by one arm 112 of a lever 115 pivotally mounted on a pin 116, secured in a portion of the housing member 106, between upper and lower collars 117 and 120, respectively, secured to the pin. The lower collar 120 is provided with an extension 121 having a pin 122 extending upwardly therefrom for engagement with a projection 125 of the lever 115 (FIGS. 11 and 13) to limit the counterclockwise movement of the lever under the influence of a spring 126 connected between the arm 112 of the lever 115 and a spring stud 127 carried in the extension 121. A second arm 130 projecting from the lever 115 is adapted to be engaged, upon the indexing of pattern drum 42, by a tooth 131 of a series of comb like members 132 secured to the pattern drum whereby lever 115 is turned clockwise to move the spring arm 111 against control button 110 to close micro-switch 101.

It is to be understood that there is a rnicro-switch 101 and lever 115 for operating the solenoid 91 associated with the cutting means at each of the feed stations, the micro-switches being supported in vertically adjacent relationship in housing 106 and the levers 115 being supported in a stack on pin 116 with their arms 112 appropriately bent to lie opposite the buttons of their associated micro-switches all as illustrated in FIG. 13. Further, each member 132 is originally provided with a tooth 13-1 for each of the levers 115 and the teeth are adapted to be broken off so that the remaining teeth on each comb like member only operates the lever 115 and microswitch for the severing means at the feed station or stations at which a yarn is to be severed at that time.

The normally closed microwswitches 105 in the operating circuits of the solenoids 91 associated with the cutting means at the several feed stations are secured to downwardly extending portions 135 of the fins 61 by screws 136. Each micro-switch 105 has a contact button 137 adapted to be engaged and depressed, to open this micro switch, by an arm 140. The arm 140 which is pivotally mounted on the micro-switch 105 is normally moved in a cloclcwise direction as viewed in FIGS. 4 and 14, to disengage the contact button 137 and permit the micro-switch to close. The arm 140 is provided with a lower offset end portion 141 having a narrow tip 142 extending downwardly into an opening 145 formed in the binder plate 52 (FIGS. 5 and 8). A pin 146 projecting from the upper cutting blade 85 engages the offset end portion 141 to turn the arm 140 counterclockwise, as viewed in FIGS. 4, 7 and 14, to depress the contact button 137 and open the micro-switch 105 when the cutting blade 85 is in its closed position. On the other hand when the cutting blade 85 is moved to its open position the pin 146 is moved out of engagement with the offset end 141 thereby permitting the arm 140 to move clockwise to the positon of FIG. 9 to release the contact button 137 and close the micro switch for purposes hereinafter set forth.

During the knitting of the active yarns at any of the feed stations, the upper cutting blade of the clamp and cutter for that station is maintained in its closed position of FIG. 7 by a spring 147 connected between the core member of its associated solenoid and the spring stud 80. The micro-switch is held open by engagement of the pin 146 with the end portion 141 of the arm 140 and the micro-switch 101 is open to maintain the solenoid 91 in de-energized condition. Also at this time the previously severed inactive yarns at that station are clamped by the clamping member 71 and clamping finger 75. During the same indexing movement of the pattern drums 42 and 45 to operate the button drum 35 to move a yarn finger 3-1 to inactive position at a feed station for the purpose of removing the yarn thereof from the fabric, which action occurs during a counterclockwise or forward movement of the needle cylinder 17, a member 132 on the pattern drum 42 is moved past the lever to cause a tooth 131 thereof to strike the lever and close the microswitch 101 and then permit this switch to immediately reopen. This momentary closing of the circuit through the switch 101 energizes and operates the solenoid 91 to raise the cutting blade 85- to its open position and move the pin 146 thereon out of engagement with the arm thereby permitting the arm to move clockwise to its position of FIG. 9 which in turn permits the switch 105 to close. Thus it will be seen that the circuit for the solenoid is initially energized through the switch 101 to open the blade 85 and the circuit for the solenoid is then energized through the switch 105 to maintain the blade in open position until the switch 105 is again opened as hereinafter set forth.

Simultaneously with the movement of the cutting blade 85 to open position, the cutting blade engages an overlying arm on the clamping member 71 to also raise this clamping member sufficiently to release the clamping pressure exerted thereby on the previously inactivated yarns. Thereupon as the needle cylinder is moved in the forward direction the newly inactivated yarn is carried by the last needle to knit it beneath the raised clamping member 71, beneath the clamping finger 75, between the cutting blades 82 and 85 and into engagement with the tip 142 of the arm 140. As the needle cylinder continues to move in the forward direction the yarn turns the arm 140 counterclockwise to depress the button 137 and open the micro-switch 105 to de-energize the solenoid 91. Upon de-energization of the solenoid 91 the core member 90 is drawn downwardly by the spring 147 to move the blade 85 to closed position to sever the yarn and to again move the pin 146 into engagement with the end portion 141 of the arm 140 to maintain the micro-switch 105 in open position.

Alternately the movement of the cutting blade to open position and the movement of the clamping member thereby to inactive position, as above set forth, may be controlled solely through the switch 101. For this purpose the switch 105 and the operating arm 140 therefor is omitted from the electrical circuit for the solenoid 91 and the arm 130 of the lever 115 is provided with an elongated end portion 149 (FIG. 15 which upon being engaged by a tooth 131 on member 132 on the pattern drum 42, acts to close the switch 101 and maintain it closed until the member 132 is again moved out of engagement with portion 149. Preferably the length of the portion 149 is substantially the same length as the indexing movement of the drum 42 which occurs during an interval which is substantially equal to one complete rotation or stroke of the needle cylinder 17. Thus the switch 101 is closed at the start of the rotation of the needle cylinder, in which the yarns are to be moved to inactive position and severed, and again opened at the end of the same rotation of the cylinder thereby insuring that all of the yarns moved to inactive position at the same time will be carried beneath the raised clamping member 71 and between the opened cutting blades before the cutting blades are closed and the clamping member is 7 again returned to clamping engagement with the binder plate 52.

When one or more yarns are to be moved to nonknitting position at a feed station but not severed from the fabric, in the manner hereinbefore set forth, the fingers 31 are moved to inactive position to raise these yarns above the binder plate 52.. At this time, however, as there is no movement of a member 132 on the pattern drum into contact with lever 130 the solenoid 91 is not energized and the cutting blade 85 remains in closed position which in turn permits the clamping member 71 to remain in clamping engagement with the binder plate. Consequently, unless prevented from doing so, the yarns as they are carried above the binder plate by the rotation of the needle cylinder will be drawn beneath the clamping member thereby causing damage to the yarns. In order to hold the yarns out of clamping means at this time there is provided a guard means comprising a lever 151 mounted for pivotal movement on the stud 72 and having an arm 152 projecting transversely therefrom to lie between the clamping member 71 and the clamping finger 75 (FIGS. 4 and 5). Adjacent its free end the arm 152 has an angularly extending front wall 155 ending at its lower end in a tip 156, and a lower horizontally extending recessed surface 157 (FIG. 9). In the lowered or active position of the arm 152, as viewed in FIG. 7, the surface 157 engages the upper surface of the binder plate 52 and the tip 156 of the arm lies Within a recess or opening 160 in the binder plate to position the lower end of the front wall 155 below the upper surface of the binder plate (FIG. 7). Also, as shown in FIG. 4, in the active position of the arm 152, the front wall 155 thereof is positioned slightly outwardly of the yarn clamping surfaces of the clamping member 71 and clamping finger 75 and acts to prevent the yarns from passing beneath the clamping member and finger. When the yarns moved to non-knitting position are not to be severed the lever 151 and arm 152 are maintained in active position by a spring 161 connected between an arm 162 of the lever and the stud 80 (FIG. 5). When the yarns are to be severed the cutting blade 85 and clamping member 71 are raised, as hereinbefore set forth, and the arm 152 must also be raised to permit the yarns to pass beneath the clamping member and between the cutting blades. For this purpose the lever 151 is provided with a tail portion 165 overlying the cutting blade 85 so that as the blade 85 is moved to its raised or open position the lever is also operated to raise the arm 152 to inactive position.

It will be understood that the improvements specifically shown and described by which the above described results are obtained can be changed in various ways Without departing from the invention herein disclosed and hereinafter claimed.

We claim? 1. In a circular knitting machine having yarn feeding means, a rotatable needle cylinder, needles carried by said cylinder for forming yarns fed by said feeding means into knitted fabric, means for moving said yarn feeding means to move the yarns fed thereby between knitting and non-knitting positions, yarn clamping means including a clamping member movable between an active yarn clamping position and an inactive position to receive yarns moved to non-knitting position, yarn severing means movable between a normally closed yarn severing position and an open position to receive yarns moved 'to non-knitting position, means for moving said yarn severing means to open position, means for moving said yarn severing means to closed position, guard means movable between an active position in which it lies in the path of yarns moved to non-knitting position to prevent said yarns from entering said clamping means and an inactive position, said means for moving said severing means to open position also acting to move said clamping member and said guard means to inactive positions.

2. In a circular knitting machine according to claim 1 in which said means for moving said severing means to open position comprises eelctrical means and pattern means for con-trolling the operation of said electrical means.

3. In a circular knitting machine according to claim 2 in which said electrical means comprises an operating circuit, means for closing and energizing said operating circuit to move said severing means to open position, and means for opening and de-energizing said operating circuit to permit movement of said severing means to closed position.

4. In a knitting machine according to claim 3 in which said means for opening and de-energizing said operating circuit is operated by the yarns moved to non-knitting positions.

5. In a circular knitting machine having yarn feeding means, a rotatable needle cylinder, needles carried by said cylinder for forming yarns fed by said feeding means into knitted fabric, means for moving said feeding means to move the yarns fed thereby between knitting and nonknitting positions, yarn severing means including a cutting blade movable between open and closed positions, means for moving said cutting blade to open position to receive yarns moved to non-knitting positions, means for moving said cutting blade to closed position to sever said yarns moved to non-knitting position, yarn clamping means including a clamping member movable between an active yarn clamping position and an inactive position to receive yarns moved to non-knitting positions, means for moving said clamping member to inactive position, said means for moving said clamping member to inactive position being operated by said cutting blade upon movement thereof to open position, guard means movable between active and inactive positions, said guard means acting when in active positiion to prevent yarns moved to nonknitting positions from entering said clamping means, and means for moving said guard means to inactive position.

6. In a circular knitting machine haw'ng yarn feeding means, a rotatable needle cylinder, needles carried by said cylinder for forming yarns fed by said feeding means into knitted fabric, means for moving said feeding means to move the yarns fed thereby between knitting and nonknitting positions, yarn severing means including a cutting blade movable between open and closed positions, means for moving said cutting blade to open position to receive yarns moved to non-knitting positions, means for moving said cutting blade to closed position to sever said yarns moved to non-knitting position, yarn clamping means including a clamping member movable between an active yarn clamping position and an inactive position to receive yarns moved to non-knitting positions, means for moving said clamping member to inactive position, guard means movable between active and inactive positions, said guard means acting when in active position to prevent yarns moved to non-knitting positions from entering said clamping means, and means for moving said guard means to inactive position, said means for moving said guard means to inactive position being operated by said cutting blade upon movement thereof to open position.

7. In a circular knitting machine having yarn feeding means, a rotatable needle cylinder, needles carried by said cylinder for forming yarns fed by said feeding means into knitted fabric, means for moving said feeding means to move the yarns fed thereby between knitting and nonknitting positions, yarn severing means including a cutting blade movable between open and closed positions, electrical means for moving said cutting blade to open position to receive yarns moved to non-knitting position, pattern means for controlling the operation of said electrical means, means for moving said cutting blade to closed position to sever said yarns moved to non-knitting position, yarn clamping means including a clamping member movable between an active yarn clamping position and an inactive position to receive yarns moved to non-knitting positions, means for moving said clamping member to inactive position, guard means movable between active and inactive positions, said guard means acting when in active position to prevent yarns moved to non-knitting positions from entering said clamping means, and means for moving said guard means to inactive position.

8. In a circular knitting machine according to claim 7 in which said electrical means comprises a solenoid connected to said cutting blade, a normally open first switch, said pattern means operating to close said switch to energize said solenoid to move said cutting blade to open position, a second switch being adapted to be closed by the movement of said cutting blade to open position to maintain said solenoid energized when said first switch is reopened, and means for opening said second switch to 10 de-energize said solenoid to permit movement of said cutting blade to closed position.

9. In a circular knitting machine according to claim 8 in which said means for opening said second switch is operated by said yarns upon movement thereof to said non-knitting positions.

10. In a circular knitting machine according to claim 8 in which said means for opening said second switch is operated by said cutting blade .to maintain said second switch open when said cutting blade is in closed position.

References Cited in the file of this patent UNITED STATES PATENTS 2,270,432 Fregeolle Ian. 20, 1942 2,924,958 Moyer Feb. 16, 1950 2,948,131 Levin Aug. 9, 1960 

1. IN A CIRCULAR KNITTING MACHINE HAVING YARN FEEDING MEANS, A ROTATABLE NEEDLE CYLINDER, NEEDLES CARRIED BY SAID CYLINDER FOR FORMING YARNS FED BY SAID FEEDING MEANS INTO KNITTED FABRIC, MEANS FOR MOVING SAID YARN FEEDING MEANS TO MOVE THE YARNS FED THEREBY BETWEEN KNITTING AND NON-KNITTING POSITIONS, YARN CLAMPING MEANS INCLUDING A CLAMPING MEMBER MOVABLE BETWEEN AN ACTIVE YARN CLAMPING POSTION AND AN INACTIVE POSITION TO RECEIVE YARNS MOVED TO NON-KNITTING POSTION, YARN SEVERING MEANS MOVABLE BETWEEN A NORMALLY CLOSED YARN SEVERING POSTION AND AN OPOEN POSITION TO RECEIVE YARNS MOVED TO NON-KNITTING POSTION, MEANS FOR MOVING SAID YARN SEVERING MEANS TO OPEN POSITION, MEANS FOR MOVING SAID YARN SEVERING MEANS TO CLOSED POSTION, GUARD MEANS MOVABLE BETWEEN AN ACTIVE POSTION IN WHICH IT LIES IN THE PATH OF YARNS MOVED TO NON-UKNITTING POSTION TO PREVENT SAID YARNS FROM ENTERING SAID CLAMPING MEANS AND AN INACTIVE POSTION, SAID MEANS FOR MOVING SAID SEVERING MEANS TO OPEN POSTION ALSO ACTING TO MOVE SAID CLAMPING MEMBER AND SAID GUARD MEANS TO INACTIVE POSITIONS. 